Investigation of thermal performance of an emitter coated with Radiative cooling paint across different Climates Conditions in Morocco

Radiative cooling paints (RCPs) are an effective, scalable, and low-cost technology to address the growing energy consumption for space cooling and to ensure energy-free cooling. this study aims to investigate an emitter coated with RCP has been mathematically described by governing heat transfer equations and numerically computed using COMSOL Multiphysics Software to evaluate their thermal behavior compared to air environment temperature and the unpainted baseline, as well as to determined their daytime and nighttime net power cooling over different climates of Morocco namely: Casablanca, Oujda, Tetouan, Tata and Errachidia. The simulation results show that the painted emitter in Tata achieved the highest sub-ambient cooling temperature reduction (8.7°C) rather than that of Oujda, Errachidia. Tetouan and Casablanca, with temperature diminution of 8.6 °C,7.7°C, 4.7°C and 4°C, respectively. However, the unpainted emitter remained nearly aligned with the ambient temperature across all studied climates. Additionally, Tata was found to be significantly the greatest net cooling power 111 W·m⁻2 at night and 86.5 W·m⁻2 during the day. This work offers key insights into application of such material to building envelopes particularly under Arid and semi-arid conditions.